Timefmt

This command applies to timeseries where data are composed of dates/times.
It has no meaning unless the command set xdata time is given also.

Syntax:

set timefmt "<format string>"
show timefmt

The string argument tells gnuplot how to read timedata from the datafile.
The valid formats are:

Time Series timedata Format Specifiers

Format

Explanation

%d

day of the month, 1-31

%m

month of the year, 1-12

%y

year, 0-99

%Y

year, 4-digit

%j

day of the year, 1-365

%H

hour, 0-24

%M

minute, 0-60

%s

seconds since the Unix epoch (1970-01-01 00:00 UTC)

%S

second, 0-60

%b

three-character abbreviation of the name of the month

%B

name of the month

Any character is allowed in the string, but must match exactly. 3#3t (tab) is
recognized. Backslash-octals (3#3nnn) are converted to char. If there is no
separating character between the time/date elements, then %d, %m, %y, %H, %M
and %S read two digits each, %Y reads four digits and %j reads three digits.
%b requires three characters, and %B requires as many as it needs.

Spaces are treated slightly differently. A space in the string stands for
zero or more whitespace characters in the file. That is, "%H %M" can be used
to read "1220" and "12 20" as well as "12 20".

Each set of non-blank characters in the timedata counts as one column in the
using n:n specification. Thus 11:11 25/12/76 21.0 consists of three
columns. To avoid confusion, gnuplot requires that you provide a complete
using specification if your file contains timedata.

Since gnuplot cannot read non-numerical text, if the date format includes
the day or month in words, the format string must exclude this text. But
it can still be printed with the "%a", "%A", "%b", or "%B" specifier:
see set format (p. ) for more details about these and other options for printing
timedata. (gnuplot will determine the proper month and weekday from the
numerical values.)

See also set xdata (p. ) and Time/date (p. ) for more information.

Example:

set timefmt "%d/%m/%Y\t%H:%M"

tells gnuplot to read date and time separated by tab. (But look closely at
your data -- what began as a tab may have been converted to spaces somewhere
along the line; the format string must match what is actually in the file.)
See also